I'm so sorry to hear you're missing the picture.
My advice to you is to locate the drive /dev/null, remove it from the computer and send it off to a professional data recovery company. I'm sure they will be most helpful.
Do remember to replace the drive once removed, (you will need to format it:
sudo dd if=/dev/random of=/dev/null
-- this may take some time) as otherwise you will not have any backup space to use.